Effective ultrasonic barking control device: The updated ultrasonic barking deterrent device makes it more convenient for you to train dogs. The 3 ultrasonic frequency levels cover most dog training. When you turn on the barking control device, it willautomatically detect the barking of the dog and send out ultrasonic waves. Once the dog is quiet, the ultrasound will stop automatically. Human safety, suitable for dogs: ultrasound will not cause any interference or harm to humans, because humanscannot hear these bands, but dogs will be sensitive to these ultrasound. Different dogs may be sensitive to different frequency bands of ultrasound. Please turn the knob to test different frequency bands for best results. Range up to 32 feet Antistripping device: ultrasonic penetration range is 50 feet, covering indoor and outdoor areas. Compared with traditional dog training equipment, it completely frees your hands. By turning the knob, you can easily train the dog's behavior. After testing,the best effect is within 50 feet. The smaller the range, the better the effect. Durable power supply u0026 waterproof u0026 easy to install: equipped with powerful battery, the barking prevention device can work continuously for 30 days after fullcharge. IPX4 waterproof material can be hung on trees, indoors, outdoors and anywhere else. Tips: The dog deterrent device is not applicable to the following situations: aggressive dogs, noisy environments, hearing impaired dogs, two or more dogstogether, dogs under 6 months or over 8 years old.